U.S. patent number 6,424,164 [Application Number 09/593,262] was granted by the patent office on 2002-07-23 for probe apparatus having removable beam probes.
This patent grant is currently assigned to Kulicke & Soffa Investment, Inc.. Invention is credited to January Kister.
United States Patent |
6,424,164 |
Kister |
July 23, 2002 |
Probe apparatus having removable beam probes
Abstract
An apparatus for electronically testing of bound electrical
circuits connected to planar arrayed pads having removable mounted
conductive beam probes to simplify the manufacturing and
maintaining process. A space transformer comprises from outside
electrically accessible conductive holes wherein the guided beam
probes are friction resilient resting. In a second embodiment, the
friction resilient resting induces a predetermined bending onto the
beam probes. This is accomplished by offsetting guiding plates thus
imposing a rotational urging on the probe neck within the
conductive hole which is just a bare extension of the beam
probe.
Inventors: |
Kister; January (Redwood City,
CA) |
Assignee: |
Kulicke & Soffa Investment,
Inc. (Wilmington, DE)
|
Family
ID: |
24374047 |
Appl.
No.: |
09/593,262 |
Filed: |
June 13, 2000 |
Current U.S.
Class: |
324/754.03;
324/754.13; 439/289 |
Current CPC
Class: |
G01R
1/07357 (20130101) |
Current International
Class: |
G01R
1/073 (20060101); G01R 031/02 () |
Field of
Search: |
;324/158.1,754,755,758,761,73.1,72.5,500,725,757
;439/482,289,259 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sherry; Michael J.
Assistant Examiner: Nguyen; Trung
Attorney, Agent or Firm: Lumen Intellectual Property
Services, Inc.
Claims
Accordingly, the scope of the invention should be determined by the
following claims and their legal equivalents:
1. A probe apparatus for contacting pads of an electrical circuit
under test, said probe apparatus comprising: a) a space transformer
with electrically conductive holes; and b) electrically conductive
beam probes, at least one of said electrically conductive beam
probes having: 1) a probe tip for contacting one of said pads; 2) a
beam section; and 3) a probe neck having a preformed mechanically
resilient section, said mechanically resilient section of said
probe neck being frictionally retained and self-supported in said
electrically conductive holes.
2. The probe apparatus of claim 1, further comprising a first plate
between said space transformer and said electrical circuit under
test, said first plate having guiding holes for accepting said beam
section of said electrically conductive beam probes.
3. The probe apparatus of claim 1, wherein said mechanically
resilient section is an undulating section.
4. The probe apparatus of claim 3, wherein said undulating section
has a spiral form.
5. The probe apparatus of claim 3, wherein said undulating section
comprises undulations in one plane.
6. The probe apparatus of claim 1, wherein said mechanically
resilient section is a lateral deformation.
7. The probe apparatus of claim 6, wherein said lateral deformation
has two contact points on opposing sides of said electrically
conductive holes.
8. The probe apparatus of claim 6, wherein said lateral deformation
comprises a number of undulations placed along said probe neck.
9. The probe apparatus of claim 6, wherein said lateral deformation
comprises two or more contact points within said conductive
hole.
10. The probe apparatus of claim 1, wherein at least one of said
electrically conductive holes are plated with a conductive
material.
11. The probe apparatus of claim 1, wherein at least one of said
electrically conductive holes terminates in a bottom surface and
said probe neck of each of said beam probes rests against said
bottom surface.
12. The probe apparatus of claim 1, wherein at least one of said
electrically conductive holes comprises a rotational positioning
means, wherein said probe neck is urged into a predetermined
rotational orientation.
13. The probe apparatus of claim 1, further comprising an
adjustment means for laterally displacing said first and changing
said lateral offset.
14. The probe apparatus of claim 1, further comprising at least one
auxiliary plate having auxiliary guiding holes for accepting said
beam section of said beam probes.
15. The probe apparatus of claim 14, wherein said auxiliary guiding
holes of said auxiliary guiding plate are offset from said guiding
holes of said first guiding plate.
16. A probe apparatus for contacting pads of an electrical circuit
under test, said probe apparatus comprising: a) a space transformer
with electrically conductive holes; b) electrically conductive beam
probes, each of said electrically conductive beam probes having: 1)
a probe tip for contacting one of said pads; 2) a beam section; and
3) a probe neck comprising a preformed mechanically resilient
section, said mechanically resilient section of said probe neck
being frictionally retained and self-supported in said electrically
conductive holes; c) a first plate between said electrical circuit
under test and said space transformer, said plate having guiding
holes for accepting said beam section of said electrically
conductive probe beam; and d) an adjustment means for laterally
displacing said first plate to introduce a lateral offset between
said first guiding holes and said electrically conductive
holes.
17. The probe apparatus of claim 16, wherein said mechanically
resilient section is a lateral deformation.
18. The probe apparatus of claim 16, wherein said conductive holes
are plated with a conductive material.
19. The probe apparatus of claim 16, wherein each of said
conductive holes terminates in a bottom surface and said probe neck
of each of said beam probes rests against said bottom surface.
20. The probe apparatus of claim 16, further comprising a second
guiding plate having guiding holes for accepting said beam section
of said beam probes.
21. The probe card of claim 20, wherein said guiding holes of said
second guiding plate are offset from said guiding holes of said
first guiding plate.
Description
FIELD OF INVENTION
This invention relates to the field of testing electrical circuits.
In particular, this invention relates to an apparatus with
removable beam probes for testing bound electrical circuits.
BACKGROUND OF THE INVENTION
In recent years electrical circuits become drastically more complex
and smaller at the same time. The numbers of contact pads for
transmitting electrical signals from an integrated circuit is
rising and the size of the pads is becoming smaller and smaller.
Such integrated circuits are usually tested while still on a wafer,
or in the bound state. For this purpose the contact pads are
contacted by suitable probes which send a series of electronic test
signals through the integrated circuit.
A number of prior art design concepts teach cantilever probes for
laterally accessing the pads. Other prior art techniques teach to
access the pads directly from above by using mechanically
resilient, conductive beam probes.
Various design solutions for arranging and guiding those so called
"buckling beam probes" have been developed. For more information
about buckling beams and probe devices employing them see, for
instance U.S. Pat. Nos. 3,806,801; 4,506,215; 4,518,910; 4,686,464
and 4,901,013.
The prior art teaches to bind or attach such buckling beam probes
in a mechanically rigid way on one end by soldering them into
sockets. Unfortunately, the adhesive and thermal influences during
the soldering process disturb the alignment of the beam probes.
Therefore, an additional alignment process is required as a final
step in the manufacturing of such beam probe assemblies. The
thinner those buckling beams become, the more difficult this
alignment process becomes.
Before an electrical circuit can be tested, it must be placed in a
testing position on a stage. The stage applies an overdrive and
lifts the circuit so that each buckling beam contacts a
predetermined pad. In most cases the contacting tip of the buckling
beam scrubs along the surface of the pad, thereby removing an
insulating oxide layer which forms on top of the pad. Those
oxidized layers are hard and cause the buckling beam's tip to
become abraded over many test cycles. This abrasion does not occur
evenly on all pads, causing individual beam tips to abrade faster
than others. In addition mechanical stress and irregularities
during the testing cycles always cause individual buckling beams to
lose their original manufactured shape.
Thus there exists a need for a probe apparatus capable of
assembling the beam probes in a way, such that the abrasive
processing of the probe tips for alignment and maintaining can be
avoided. Additionally, it would be an advance over the prior art to
provide a probe apparatus in which the beam probes can be
individually replaced. Thus, damaged beam probes could be simply
removed and new beam probes inserted in their place.
OBJECTS AND ADVANTAGES
Accordingly, it is a primary object of the present invention to
provide a probe apparatus equipped with beam probes which are
self-supporting, resilient and removable. It is a further object of
the invention to assembly the beam probes in such a way, that
during the testing process the beam probes are kept in aligned
position to assure the same contact characteristic for each
individual beam probe with the designated pad. It is another object
of the invention to assembly the beam probes in a way, that a
predetermination of the spring characteristic is possible. It is an
additional object of the invention to assembly beam probes with a
minimal lateral deformation to achieve the highest possible beam
probe density. Further objects and advantages will become apparent
upon reading the detailed description.
SUMMARY
The object and advantages of the invention are secured by a probe
apparatus for contacting pads of an electrical circuit under test.
The probe apparatus has a space transformer with a number of
electrically conductive holes. The conductive holes can be plated
with a conductive material such that they offer an electrically
conductive inner surface. The conductive inner surfaces of the
holes are connected via horizontal and vertical conductors to
connectors on the surface of the space transformer. Those
connectors are in electrical communications with the circuitry
required to perform the test. The space between the connectors is
sufficient for accommodating cables for transmission of other
electrical signals. The horizontal and vertical conductors are part
of conductor carrier plates, which are a stacked and bound to form
a part of the space transformer.
Electrically conductive beam probes are inserted into the
conductive holes. The beam probes have a probe tip for contacting
the pads, a beam section and a probe neck with a mechanically
resilient feature. The beam probes are inserted into the holes by
their necks such that the resilient feature frictionally retains
the neck. As a result, the beam probe is retained in the hole due
to friction resistance.
The mechanically resilient feature retaining the beam probes in the
holes can be an undulating section such as a section having a
spiral form or a sections with undulations confined to one plane.
Alternatively, the resilient feature can be a lateral deformation
or a number of deformations which may contact the hole on two
opposite sides and at a number of contact points.
Preferably, the holes terminate in a bottom surface and the probe
neck of each beam probe rests against this bottom surface. This
approach allows the user to achieve better planarity between the
probe tips. In addition, the holes may have a rotational
positioning feature, such that the neck is urged into a
predetermined rotational orientation when inserted. In a first
embodiment the probe neck comprises one, two or more lateral
manufactured deformations exceeding the contour shape of the
conductive hole in disassembled comparison. The lateral
deformations can have an undulating shape, expanding in one or more
planes or in spiral arrangement. A resilient lateral urging is
imposed at a number of contact points on the probe when inserted
into the conductive hole.
The probe apparatus can additionally have plates with guiding holes
for receiving the beam sections of the beam probes. Also, one or
more auxiliary plate can be provided. The holes in the plates can
be offset from the holes in the space transformer. In one
embodiment, the probe apparatus has a mechanism for laterally
displacing the plate and changing the lateral offset. It should
also be noted that the holes in the plate can be offset from the
holes in the auxiliary plates.
The position and amount of resilient urging of the beam contact
points in the conductive hole defines a rotational urging or torque
on the beam probe, wherein the rotational urging from only two beam
contact points is free of any deflective influence on the probe
neck itself. This rotational urging is transmitted onto the beam
section and opposed through the guiding holes of one or more of the
guiding plates. Such rotational positioning feature may simply be
provided by holes with oval or elliptical cross-sections.
In a second particular embodiment the lateral urging on the probe
neck is imposed by a rotational urging of the probe neck exceeding
the hole boundaries. The rotational urging is imposed by a
predetermined bending of the beam section by offsetting the guiding
holes of one or more guiding plates out of the alignment along the
manufactured shape of the beam section.
The predetermined bending provides a desired spring characteristic
over the length of the beam probe against impact of the pad moving
towards the probe tip while the bound electrical circuit is placed
into testing position.
In yet another embodiment utilizing a first plate with guiding
holes the beam probes have necks with mechanically resilient
sections. When the necks are inserted into the guiding holes the
plate is moved by an adjustment mechanism which laterally displaces
the plate. This introduces a lateral offset between the holes in
the space transformer and the guiding holes causing the
mechanically resilient section to be frictionally retained in the
conductive hole. Thus, the beam probes are retained in the space
transformer. Of course, the mechanically resilient section may have
a mechanically resilient feature such as a lateral deformation or a
section which is straight when no mechanical stress is applied.
The details of the invention are explained in the detailed
description in reference to the attached drawing figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective fragmental view of the first embodiment of
the invention.
FIG. 2 is a schematic view of the first embodiment of the
invention.
FIG. 3 is an enlarged fragmental view of FIG. 2.
FIG. 4 is a perspective fragmental view onto a cut section of the
space transformer along an array of conductive holes, showing a
variation of the first embodiment of the invention.
FIG. 5 is a schematic view of a variation of the first embodiment
of the invention with two lateral deformations on a blank probe
neck.
FIG. 6 is an enlarged fragmental view of a variation of the first
embodiment of the invention with one lateral deformation on a blank
probe neck.
FIG. 7 is a schematic view of the second embodiment of the
invention.
FIG. 8 is an enlarged fragmental view of FIG. 6.
DETAILED DESCRIPTION
Although the following detailed description contains many specifics
for the purposes of illustration, anyone of ordinary skill in the
art will appreciate that many variations and alterations to the
following details are within the scope of the invention.
Accordingly, the following preferred embodiment of the invention is
set forth without any lose of generality to, and without imposing
limitations upon, the claimed invention.
A preferred embodiment of the invention is shown in FIG. 1. FIG. 1
shows the fragmental shape of a space transformer 5 comprising a
plurality of electrically conductive holes 1 and a stack of
conductor carrier plates 13 as they are bound together in the
central area of space transformer 5. Vertical conductors 4 and
horizontal conductors 3 electrically connect the outside accessible
connectors 2 with the conductive holes 1. FIG. 1 shows only those
conductive holes 1 and vertical conductors 4 that become visible
where the fragment of the space transformer 5 broken off. A
plurality of probe necks 6 is visible where they would be
positioned within conductive holes 1 of the missing fragment of
space transformer 5.
A plurality of beam probes with their blank probe necks 6, their
probe tips 11 and their probe sections 7 is guided in a plurality
of guiding holes 12 of a first guiding plate 8. Guiding plate 8 is
displayed as a fragment such that an electrical circuit under test
10 comprising a plurality of pads 9 is visible in testing position.
In this view probe tips 11 touch pads 9 of circuit 10.
The illustrated assembly is the main functional part of the
apparatus. Frame elements, fixtures, cables and other common
elements of this apparatus are not shown. The main function of
space transformer 5 is to provide conductive holes 1, which are
placed so tight together, that a distributing means must be
provided. Vertical conductor 4 reaches through layers of carrier
plates 13 that distribute the electrical signals with their
horizontal conductors 3 in a predetermined way to the outside
accessible connectors 2. The connectors 2 are placed on the outside
periphery of space transformer 5 in sufficient distance to each
other, so that cables for further transmission of signals to and
from a testing circuit can be easily attached without unreasonable
spatial constraints.
Conductive holes 1 are placed in an array arrangement and are in
electrical contact with the arrangement of pads 9. Each conductive
hole 1 holds by means of a friction hold the mechanically resilient
probe neck 6 that continues as a mechanical resilient beam section
7. Conductive holes 1 can have a rotationally symmetric shape or a
particular pronounced contour, e.g., an elliptical or oval contour,
to urge probe neck 6 into a predetermined rotational orientation.
This predetermined rotational orientation can be also achieved by
shaping beam section 7 such that guiding holes 12 of first guiding
plate 8 capture beam section 7 in an offset position from the
rotational axis of guiding hole 12.
Space transformer 5 and guiding plate 8 are independently mounted,
such that the conductive holes 1 are accessible during the
manufacturing of the apparatus. Preferably, guiding plate can be
shifted or moved by an adjustment means 30, to alter the offset
between conductive holes 1 and guiding holes 12.
Electrical circuit 10 is held in testing position such that pads 9
are aligned with the corresponding probe tip 11. The length and
shape of beam section 7 allow the beam probe to deflect by a
predetermined amount, to provide a resilient contact between probe
tips 11 and pads 9. Specifically, the length and shape of beam
section 7 is calculated to obtain desired scrub characteristics of
tip 11 on pad 9.
Beam sections 7 are preferably covered with and insulating layer to
avoid electrical contact between them. The beam probes are
manufactured from wire material. The specific shaping of the probe
neck 6 are achieved by one or more bending operations or by plastic
deformation of the section shape of the wire material.
FIG. 2 is a schematic view of the first embodiment of the invention
showing a fragment of space transformer 5 in a cross sectional
view, illustrating conductive holes 1 and vertical conductors 4.
The blank probe necks 6 are fully visible in assembled position.
Guiding plate 8 is also in fragmental cut view such that each beam
section 7 is fully visible in its predetermined bending position
guided through guiding holes 12. Each probe tip 11 touches a
corresponding pad 9 of electrical circuit 10 in testing position.
This schematic view gives a clear understanding about the inventive
concept. It shows, how the resilient deflection of each probe neck
6 with an undulating resilient feature imposes a rotational urging
on beam section 6. Since beam section 7 is held in position at its
lower end by guiding holes 12, the rotational urging or torque
causes beam section 7 to bend out of its manufactured shape. For
example, as show in FIG. 1 the manufactured shape is meant to be
straight; thus the bending of beam section 7 is obvious. Guiding
holes 12 are laterally offset from the rotational axis of
conductive hole 1 urging the beam probes into the same rotational
orientation in assembled position. Guiding plate 8 with the lateral
offset therefore is essential for a proper positioning and
retention of the beam probes within the assembly.
FIG. 3 is an enlarged fragmental view of FIG. 2, showing a fragment
of space transformer 5 in a cross-sectional view showing vertical
conductors 4 and conductive holes 1. A smaller number of beam
probes 7 with their probe necks 6 is visible in assembled position
inserted into conductive holes 1. Each blank probe neck 6 is shown
for example with a plurality of first, second and third lateral
deformations 22, 21, 20 exposed to lateral urging on contact at a
first, second and third contact points 17, 16, 15 with a conductive
surface 18 of conductive holes 1. Each probe neck 6 touches with a
vertical beam alignment contact 19 at a hole bottom 14, whereby a
predetermined longitudinal position of the beam probe within
conductive holes 1 is imposed.
In FIG. 3 lateral deformations 22, 21, 20 are shown for example as
bends or undulations in one plane. Depending on placement and
number of contact points 17, 16, 15 (in this case three) along two
or more planes, or on opposite sides of holes 1, probe neck 6 can
have a uniform radial cross section and its longitudinal shape will
determine its final position within conductive hole 1. In that
case, the guiding plate is necessary to provide a rotational
orientation. The resilient deflection of probe neck 6 between the
lateral deformations 22, 21, 20 imposes a rotational urging or a
torque on beam section 7. Electrically conductive surface 18 is a
metal, e.g., copper, plated on the inner surface of conductive
holes 1. During the assembly the probe necks are placed or inserted
into conductive holes 1. The friction resistance at contact points
15, 16, 17 is defined by the amount by which lateral deformations
22, 21, 20 exceed the cross-sectional dimension or inside contour
of conductive hole 1. The frictional resistance is high enough to
hold the beam probes with their weight against gravitational forces
and with their mass against acceleration forces in assembled
position. In other words, the neck is retained within hole 1 with
sufficient force to retain entire beam probe. Acceleration forces
occur through external forces and movements imposed onto the
apparatus. The friction resistance is low enough to accomplish an
assembly within the conductive holes, without deforming beam
section 7.
FIG. 4 is a perspective fragmental view of a cross-section of space
transformer 5 along an array of conductive holes 1, showing a
variation of the first embodiment of the invention. For example,
space transformer 5 is shown cut through along an array of
conductive holes 1. Conductive holes 1 with their conductive
surface 18, their hole bottom 14 and vertical conductor 4 are also
shown cut along the same plane. Each probe neck 6 is shown in the
form of a spiral. The spiral shape of probe neck 6 allows a linear
contact between probe neck 6 and conductive surface 18. Probe neck
6 has a longitudinal resilience against the impact or force
translated from pads 9 as they are brought into testing position.
Probe neck 6 is resting in a radially and longitudinal well-defined
position. A guiding plate is just necessary to provide a rotational
orientation. The enhanced spring characteristic of probe neck 6
allows a minimal scrubbing between the probe neck 6 and the
conductive surface 18 to keep the contact area free of insulating
oxidation layers.
FIG. 5 is a schematic view of a variation of the first embodiment
of the invention showing for example a fragment of space
transformer 5 in cross-sectional view, illustrating conductive
holes 1 and the vertical conductors 4. First guiding plate 8 and an
auxiliary guiding plate 23 with a plurality of auxiliary guiding
holes 12, 24 are also shown. Beam probes 7 are fully visible in
their predetermined bending direction guided through guiding holes
12, 24. Each probe tip 11 is touching on the corresponding pad 9 of
electrical circuit 10 under test.
Each probe neck 6 has a first and a second lateral deformation 21,
22. The rotational urging is imposed on beam section 7 by opposing
lateral urging at the contact points and the longitudinal offset
along the probe neck 6. In case of only two contacting points as
shown in FIG. 5 the rotational urging is not opposed by an internal
bending resistance as it was described for FIG. 3. Thus a much
higher rotational force is imposed on the beam section 7. To
support this higher rotational urging auxiliary guiding plate 23 is
positioned in an area of maximum deflection of beam section 7.
FIG. 6 shows a fragment of space transformer 5 in cross-sectional
view. A number of beam probes 7 with their blank probe neck 6 is
visible in assembled position inserted into conductive holes 1. In
this embodiment each probe neck 6 has a sole lateral deformation 22
exposed to lateral forces at first and second contact points 17, 16
with conductive surface 18 of the conductive holes 1. This forces a
free rotational urging on probe neck 6. Blank probe neck 6 touches
with a vertical beam alignment contact 19 at hole bottom 14, such
that a predetermined longitudinal position of neck 6 within the
conductive hole 1 is imposed.
In the embodiment of FIG. 6 even with only one lateral deformation
22 the required minimal number of two opposing contact points 16,
17 is achieved. Thus, the end of probe neck 6 is contacting on the
hole bottom 14 and conductive surface 18 simultaneously.
In another variation of the example shown in FIG. 5 the singular
lateral deformation 22 is not manufactured by a bending operation,
but by squeezing the contour shape of the wire profile of the beam
probe. In that manner a more or less symmetric positioning of first
and second beam contact points 17, 16 can be defined. The closer
first and second beam contact points 17, 16 are positioned, the
higher the lateral urging against the conductive surface 18 in
proportion to the rotational urging on beam section 7. By squeezing
the profile the section shape becomes also a profile contour less
flexible and with higher strength in the direction of the
rotational urging. No rotational urging occurs, if first and second
contact points 17, 16 are on the same longitudinal position. If the
proportion of depth and width of conductive holes 1 is adjusted
such that the probe neck can be inserted at an angle, and such that
the lateral distance between the two contact points 17, 16 is
reduced enough to allow assembly, a locking effect is achieved in
the final orientation of neck 6.
FIG. 7 is a schematic view of the second embodiment of the
invention showing a fragment of space transformer 5 in
cross-sectional view. Guiding plate 8 and an auxiliary guiding
plate 23 with a plurality of guiding holes 12, 24 are also in
fragmental cross-sectional view such that beam sections 7 are fully
visible in their predetermined bent positions guided through
guiding holes 12, 24. Each probe tip 11 is touching pad 9 of bound
electrical circuit 10 in testing position.
Probe neck 6 in this case is a mechanically resilient section.
Specifically, neck 6 is a straight continuation of beam section 7.
The rotational tendency of the beam probe is limited by resilient
contact between neck 6 and conductive surface 18 at first and
second beam contact points 17, 16. These contact points cause a
lateral urging on probe neck 6. The beam probe in the second
embodiment of the invention has a continues profile shape without
any lateral deformations on the probe neck section 6. Of course, it
is possible for neck 6 to have mechanically resilient features, as
described above.
This probe apparatus is most easily assembled by passing the beam
probes through guiding holes 12, 24 which are in aligned position
along the manufactured shape of the beam probes during the assembly
process. A lateral offset is applied to one or more guiding plates,
in this case plates 8, 23 with the aid of an adjustment means 30
after the assembly is complete. The most practical variation of the
second embodiment of the invention are straight beam probes,
allowing a straight alignment of guiding holes 12, 24 with
conductive holes 1 and a linear assembly of beam probes. The second
embodiment of the invention accommodates the highest density of
beam probes. The width of conductive holes 1 only needs to
guarantee the successful placement of the beam probes. No
dimensional considerations as they are necessary for a soldering
process limit the narrowing of the lateral distance between the
beam probes. The closer auxiliary guiding plate 23 is placed to
conductive holes 1, the more effective the rotational urging on the
probe neck.
FIG. 8 is an enlarged fragmental view of FIG. 6, showing a fragment
of the space transformer 5 in cross-section. A small number of beam
sections 7 with their blank probe necks 6 is visible in assembled
position inserted into conductive holes 1. Blank probe necks 6 are
a continuation of beam sections 7 exposed to lateral urging by
contact forces at contact points 16, 17 with conductive surface 18
of conductive holes 1. Each probe neck 6 touches with a vertical
beam alignment contact 19 hole bottom 14, whereby a predetermined
longitudinal position of probe neck 6 within conductive hole 1 is
imposed. The rotational urging imposed on beam section 7 causes
probe neck 6 to press laterally at second beam contact point 16 and
in an opposing direction at beam contact point 17 close to the edge
of conductive hole 1.
The conductive holes 1 may have cross-sections that are other than
circular. In combination with fabrication techniques that utilize
masks, the cross sections may be defined in combination with the
resolution characteristics of the selected masking technique. For
the example of a masking technique with a square pixel resolution,
the cross section of the conductive holes 1 may be rectangular
and/or square.
For other than circular cross sections of the conductive holes 1,
the cross sections of the beam probes 7 may be circular and/or
rectangular and/or square. In addition, the cross section of the
conductive holes 1 may have a geometry that corresponds to the
manner the contact pads 9 are arranged. For instance, in the case
when the contact pads 9 are arranged in a body-centered manner, the
cross sections of the conductive holes 1 and/or the beam probes 7
may be triangular.
In the case when the beam probes have a cross section that
corresponds with its geometry to that of the conductive holes 1,
the first, second and third contacting points 17, 16, 15 may become
contacting lines.
Further, in the case of conductive holes 1 with cross section that
are other than circular, the first, second and/or third lateral
deformations 22, 21, 20 may be oriented in correspondence with
corners and or lateral section extensions of the conductive holes
1.
* * * * *